Renewable sleeve assembly for rotary pump shafts



Aug. 18, 1942.

H. HlLLlE R Filed Jan. 23, 1941 VZ /A\\ INVENTOR HAROLD H/LL/ER ewfl hwm ATTORNEYS Patented Aug. 18, 1942 RENEWABLE SLEEVE ASSEMBLY FOR ROTARYPUMP SHAFTS Harold Hillier, Cathcart, Glasgow, Scotland, as-

ow, Scotland, a cor and Northern Irelan Application January 23, 1941,Serial No.

signor to G. & J. Weir, Limited, Cathcart, Glasporation of Great BritainIn Great Britain April 20, 1940 1 Claim.

This invention relates to renewable sleeves for the shafts in Way of theglands in rotary feed pumps, particularly pumps operating with stuffingboxes subject to high pressures.

In the use of stuifing boxes in rotary pumps subject to high suctionpressures it has been found requisite to maintain a considerablepressure between the packing in the stuffing box and the shaft toprevent the leakage of an undue amount of liquid to the exterior of thestuffing box. This pressure between the stuffing box packing and theshaft gives rise to wear of the shaft, and such Wear increases with thepressure to which the stuffing box is subjected. It is common practiceto fit a renewable sleeve coaxially around the shaft in way of thestufiing box packing so that any wear caused by the packing occurs onthe sleeve which can be replaced at considerably less cost than theshaft; further, such a sleeve can be made of a much more wear-resistantmaterial than the shaft which must carry the torque necessary to drivethe pump impellers.

The replacement of renewable sleeves of known construction requires thedismantling of the internal parts of the pump; frequently it isnecessary to dismantle the suction or discharge pipework and valves,and, in some cases, the driving motor.

Where the pump is driven by a steam turbine, it is often necessary toremove the steam and exhaust connections of the turbine and to open upthe turbine to permit the shaft to be removed for the purpose ofchanging the renewable sleeves. These operations require a good deal oftime and labour, with attendant cost, and in many pumping installationsthe lack of availability of the pumping and associated equipment duringsuch operations is an extremely serious and costly disadvantage, and isfrequently very inconvenient.

The necessity for changing the renewable shaft sleeves in way of thestuffing boxes arises frequently in the use of rotary pumps which areoperated at high suction pressures such as are experienced, for example,in boiler feed Water pumps and boiler circulating pumps used inconnection with forced circulation boilers.

The object of the present invention is to provide means whereby therenewable sleeve in way of the stuffing box packing is reduced to aminimum amount of material and can be replaced without dismantling anyparts of the pump or driving unit other than the stuffing box glands andwithout disturbing any of the piping or other connections to the pump orits driving unit.

The present invention consists in a renewable sleeve assembly for arotary pump shaft and stuffing box, including an easily renewablelongitudinally split sleeve which is maintained in position on the shaftby means carried by the shaft and engaging the ends of said splitsleeve.

Thus, the renewable split sleeve may be held in position by twocircumferentially continuous sleeves disposed one at each end andarranged to grip the split sleeve, the three sleeves being held togetheraxially between an abutment on the shaft and a nut.

In the accompanying drawing the figure is a section through a pumpstuffing box and shaft showing a renewable sleeve assembly in accordancewith the invention.

Referring to the drawing, the pump casing l is provided with adetachable stufiing box 2 which, however, may be formed integral withthe casing I. The stuffing box 2 is provided with a neck ring 3 andaccommodates several turns of packing 4 which are maintained in positionby a gland 5. The pump shaft 6 is provided with a shoulder 1 againstwhich abuts one end of an inner cylindrical sleeve 8, the opposite endof which is provided with an annular conical recess 9. A similarcylindrical sleeve I0 is arranged at the outer end of the gland and isprovided at its inner end with an annular conical recess H. Between theinner sleeve 8 and the outer sleeve In there is interposed a splitsleeve I2, machined at the ends to form two conical portions [1 whichare gripped in the conical recesses 9 and H formed in thecircumferentially-continuous cylindrical sleeves 8 and ID. The halves ofthe sleeve l2 have abutting longitudin'al faces at l3 which are heldtightly together by the grip of the sleeves 8 and [0. The bore of thesleeve l2 may be slightly larger in diameter than the shaft 6, as shown,to ensure that the faces [3 shall make contact. Coaxial relation of theshaft 6 and the halves of the sleeve [2 is ensured by the sleeves 8 andIll.

Force exercised by the nut I4 through the sleeve I i) causes therecesses 9 and H in the sleeves 8 and ill to grip the cones H on thesleeve l2, so that the faces l3 are pressed into contact and the sleeveI2 is restrained in coaxial relation with the shaft 6. The depth of therecesses 9 and II, and the length of the cones ll relative to the taperare such that the contact between the sleeves 8 and I0 and the sleeve 12is made on the tapered diameters only.

With the tapered construction shown, axial movement of the nut l4ensures an adequate force to ensure tightness between the faces l3.Moreover, the removal of the sleeves l0 and I2 is greatly facilitated,since a slight axial movement releases the grip on the sleeve I2.

slackening back of the nut I4 is prevented by a locking nut l5. It willbe seen that, if the nuts l5 and I4 and the sleeve H) are movedoutwards, the sleeve l2 can be removed and replaced without disturbingany parts other than those mentioned and the gland 5. The sleeve. I2 isthe only component of which renewal is necessitated by wear due to thepressure of the packing 4.

What I claim is:

In combination with a rotary shaft, a stufling box, packing within saidstufling box, a sleeve surrounding the shaft between the packing and theshaft, the ends of the sleeve being tapered conically, acircumferentially-continuous annulus carried by the shaft at each end ofthe sleeve, said annuli having conical recesses mating with the taperedends of the sleeve, an abutment on the shaft beyond one end of thesleeve which is engaged by the annulus at that end of the sleeve, and anut threaded onto the shaft beyond the other end of the sleeve andholding the sleeve and the annuli together axially and in sealingrelation on the shaft, the sleeve being split so that when the nut andthe annulus adjacent thereto are backed ofi the sleeve may be removedwithout being slipped off an end of the shaft.

HAROLD HILLIER.

